Satellite Band Structure in Silicon Caused by Electron-Plasmon Coupling

TL;DR

This study uses angle-resolved photoemission to explore silicon's wave-vector dependent plasmon satellites, revealing the absence of plasmarons and emphasizing the importance of electron correlation effects.

Contribution

First experimental observation of silicon's plasmon satellite structure with theoretical analysis showing no plasmaron formation.

Findings

Good agreement between theory and experiment for satellite dispersion

No evidence of plasmarons in silicon from first-principles calculations

Highlights the role of electron correlation in satellite features

Abstract

We report the first angle-resolved photoemission measurement of the wave-vector dependent plasmon satellite structure of a three-dimensional solid, crystalline silicon. In sharp contrast to nanomaterials, which typically exhibit strongly wave-vector dependent, low-energy plasmons, the large plasmon energy of silicon facilitates the search for a plasmaron state consisting of resonantly bound holes and plasmons and its distinction from a weakly interacting plasmon-hole pair. Employing a first-principles theory, which is based on a cumulant expansion of the one-electron Green's function and contains significant electron correlation effects, we obtain good agreement with the measured photoemission spectrum for the wave-vector dependent dispersion of the satellite feature, but without observing the existence of plasmarons in the calculations.